[regexp] Avoid side effects between map load and fast path check

[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
TBR=yangguo@chromium.org
NOPRESUBMIT=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2818683005
Cr-Commit-Position: refs/branch-heads/5.8@{#67}
Cr-Branched-From: eda659cc5e307f20ac1ad542ba12ab32eaf4c7ef-refs/heads/5.8.283@{#1}
Cr-Branched-From: 4310cd02d2160b1457baed81a2f40063eb264a21-refs/heads/master@{#43429}
Committed: https://chromium.googlesource.com/v8/v8/+/5c39a615569250e40414dcdb7a6d60a326c51ebb

[jgruber, 2017-04-15 07:59:58]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-15 08:00:03]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-15 08:00:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-15 08:00:05]

Dry run: CLs for remote refs other than refs/heads/master must contain
NOTRY=true and NOPRESUBMIT=true in order for the CQ to process them

[jgruber, 2017-04-15 08:02:31]

jgruber@chromium.org changed reviewers:
+ adamk@chromium.org

[jgruber, 2017-04-15 08:02:31]

Hey Adam, this is a manual backmerge for
https://bugs.chromium.org/p/chromium/issues/detail?id=709029. It includes only
the relevant parts (reloading the map for the fast path checks) of the original
CL. PTAL

[jgruber, 2017-04-15 08:04:49]

Description was changed from

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
==========

to

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
NOPRESUBMIT=true
NOTRY=true
==========

[jochen (gone - plz use gerrit), 2017-04-17 16:21:21]

jochen@chromium.org changed reviewers:
+ jochen@chromium.org

[jochen (gone - plz use gerrit), 2017-04-17 16:21:21]

lgtm

[jgruber, 2017-04-17 16:22:30]

Description was changed from

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
NOPRESUBMIT=true
NOTRY=true
==========

to

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
TBR=yangguo@chromium.org
NOPRESUBMIT=true
NOTRY=true
==========

[jgruber, 2017-04-17 16:22:38]

The CQ bit was checked by jgruber@chromium.org

[commit-bot: I haz the power, 2017-04-17 16:22:44]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-17 16:22:55]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492446158417380, "parent_rev":
"39cf34356426638fa975cfbe3f7d7885b49f4a84", "commit_rev":
"5c39a615569250e40414dcdb7a6d60a326c51ebb"}

[commit-bot: I haz the power, 2017-04-17 16:23:02]

Description was changed from

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
TBR=yangguo@chromium.org
NOPRESUBMIT=true
NOTRY=true
==========

to

==========
[regexp] Avoid side effects between map load and fast path check

Loading the map, performing a side-effect, and then using the stored
pointer for the fast-path check is another antipattern that can lead to
unintended shapes on the fast path.

Backmerge of commit db61537afcbc4ed1914152aad302a9788bc80d0f.

BUG=chromium:709029
TBR=yangguo@chromium.org
NOPRESUBMIT=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2818683005
Cr-Commit-Position: refs/branch-heads/5.8@{#67}
Cr-Branched-From:
eda659cc5e307f20ac1ad542ba12ab32eaf4c7ef-refs/heads/5.8.283@{#1}
Cr-Branched-From:
4310cd02d2160b1457baed81a2f40063eb264a21-refs/heads/master@{#43429}
Committed:
https://chromium.googlesource.com/v8/v8/+/5c39a615569250e40414dcdb7a6d60a326c...
==========

[commit-bot: I haz the power, 2017-04-17 16:23:03]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/5c39a615569250e40414dcdb7a6d60a326c...

[adamk, 2017-04-17 17:42:40]

lgtm, but jochen beat me to it. Thanks for the fix!